Rotational Isomers as Studied by Electronic Spectra

本文用各种电子光谱和超音速射流技术研究了几种邻位和间位取代苯酚的旋转异构体。结果发现，从OH基团的取向所产生的旋转异构体很容易识别由它们的电子激发能。用双色电离阈光谱法准确测定了各旋转异构体的电离势。所研究的分子的不同旋转异构体的电离势显示出高达200 cm-1的巨大差异<-1>，这表明通过电离方法分离旋转异构体的可能性。从超音速射流中的电子光谱还发现，旋转异构体选择性地与特定的溶剂分子形成络合物。对转动异构体的大振幅运动和分子内氢键也进行了详细的研究。

The rotational isomers of several o- and m-substituted phenolos have been studied by using various electronic spectroscopies combined with the supersonic jet technique. It was found that the rotational isomers arising from the orientation of the OH group are easily identified by their electronic excitation energies. The ionization potentials of the individual rotational isomers were accurately determined by two-color ionization threshold spectroscopy. The ionization potentials of the different rotational isomers of the molecule studied show a great difference as large as 200 cm^<-1>, which suggests the possibility of separation of the rotational isomer by the ionization method. It was also found from the electronic spectra in supersonic jets that the rotational isomer selectively forms the complexes with particular solvent molecules. The large amplitude motion and intramolecular hydrogen bonding in the rotational isomer were also studied in detail.